Tuberculosis

What is tuberculosis?

Tuberculosis is a serious disease caused by a bacterial infection of the lungs but can also affect other parts of the body, such as the brain, kidneys and bones. Tuberculosis, commonly known as TB, is caused by the bacterium Mycobacterium tuberculosis (M. tuberculosis).

The World Health Organization estimates that one-third of the world’s population is currently infected with tuberculosis. Globally, 86% of tuberculosis cases occur in Africa, Southeast Asia, and the Western Pacific (Source: WHO).

Tuberculosis is a contagious disease that spreads when an infected person coughs or sneezes. This shoots droplets contaminated with M. tuberculosis bacteria into the air where they can be inhaled into the lungs by others.

People who have healthy immune systems are often able to resist illness after being infected with M. tuberculosis bacteria. These people have no symptoms because the healthy immune system is able to prevent the bacteria from growing and multiplying.

In these cases, tuberculosis is called latent. People with latent tuberculosis are not contagious and cannot spread the disease to others. However, anything that stresses the immune system, such as malnutrition or a chronic disease, can lower the body’s resistance and allow the bacteria to become active and multiply in the body.

When the M. tuberculosis bacteria are able to grow and multiply, this is called active tuberculosis. Active tuberculosis often affects the lungs. People with active tuberculosis appear sick and have symptoms, such as a long-term cough.

Tuberculosis is generally treatable with medication, but some new emerging strains of tuberculosis are resistant to many antituberculosis drugs. This makes treatment more difficult in some cases.

Left untreated, an active tuberculosis infection can spread in the body and result in serious damage to the lungs and other vital organs. Tuberculosis can eventually lead to death.